Transformations, nuclear

Numerous nuclear transformations have been induced by processes in which atoms have been bombarded with neutrons, protons, deuterium, carbon atoms and ions. 

Radioactive transformations are accomplished by several different mechanisms, most importantly alpha ptirticle, beta particle, tuid gamma ray emissions, Each of tliese mechanisms are sponuuieous nuclear transformations. The result of these transformations is tlie formation of different tuid more stable elements. 

Several different mechanisms, most importtuitly alplia particle, beta particle, and gamma ray emissions accomplish radioactive transformations. Each of these mechanisms is a spontaneous nuclear transformation. Tlie result of tliese transformations is the formation of different stable elements. Tlie kind of transformation that will ttike place for any given radioactive element is a function of the type of nuclear inslabilitv as well as the mass/energy relationship. The nuclear instability is dependent on the ratio of neutrons to... 

Kem-umwandlung, /. nuclear transformation, transmutation, -verknlipfung,/. linkage to a nucleus, -verschmelzimg, /. nuclear fusion, -weehselwirkung, /. nuclear interaction, -werkstoff, m. core material. -woUe,/. prime wool, -zahl, /. number of nuclei, -zelle, /. nuclear cell, -zerfall, m. nuclear disintegration. -zerplatzen, n. nuclear explosion or disintegration. 

Radioactivity The ability possessed by some natural and synthetic isotopes to undergo nuclear transformation to other isotopes, 513 applications, 516-518 biological effects, 528-529 bombardment reactions, 514-516 diagnostic uses, 516t discovery of, 517 modes of decay, 513-514 nuclear stability and, 29-30 rate of decay, 518-520,531q Radium, 521-522 Radon, 528 Ramsay, William, 190 Random polymer 613-614 Randomness factor, 452-453 Raoult s law A relation between the vapor pressure (P) of a component of a solution and that of the pure component (P°) at the same temperature P — XP°, where X is the mole fraction, 268... 

Determine the particle emitted and write the balanced nuclear equation for each of the following nuclear transformations (a) sodium-24 to magnesium-24 (b) l28Sn to 128Sb (c) lanthanum-140 to barium-140 (d) 228Th to 224Ra. 

Henglein, A., Muccini, G. A., Chemical Effects of Nuclear Transformations, pp. 89-98, International Atomic Energy Agency, Vienna, 1961. 

Chemical Effects of Nuclear Transformations. I.A. E. A. Symposium, Vienna 1961. Chemical Effects of Nuclear Transformations. I.A.E.A. Symposium, Vienna 1965. Willard, J. E. Chemical Effects of Nuclear Transformations. Ann. Rev. Nucl. Sci. i, 193—220 (1953). 

One hundred years after the discovery of radioactivity and fifty years after the dawn of the nuclear age, society continues to debate the benefits and costs of nuclear technology. Understanding nuclear transformations and the properties of radioactivity is necessary for intelligent discussions of the nuclear dilemma. In this chapter, we explore the nucleus and the nuclear processes that it undergoes. We describe the factors that make nuclei stable or unstable, the various types of nuclear reactions that can occur, and the effects and applications of radioactivity. 

Nuclear transformations always obey two fundamental conservation laws ... 

In March 1989, Martin Fleischmann and Stanley Pons reported their discovery of cold nuclear fusion. They announced that during electrolysis of a solution of hthium hydroxide in heavy water (DjO) with a cathode made of massive palladium, nuclear transformations of deuterium at room temperature can be recorded. This announcement, which promised humankind a new and readily available energy source, was seized upon immediately by the mass media in many countries. Over the following years, research was undertaken worldwide on an unprecedented scale in an effort to verify this finding. 

More particularly, a serious breakthrough was achieved in the methods of electrochemical calorimetty. Initial conclusions as to anomalous heat evolution during the electrolysis of solutions prepared with heavy water were caused by an incorrect formulation of control experiments in light water. In fact, none of the communications confirming anomalous heat evolution have been free of procedural errors, so that one cannot even discuss a sporadic observation of this effect. In contrast to all other experimental manifestations, heat evolution is indicative of any possible nuclear transformation, which implies that in its absence, neither reaction (33.4.1) nor reaction (33.4.2) can be suggested to occur. 

After effects of nuclear transformations in solids Biological systems Minerals... 

Activity—The number of radioactive nuclear transformations occurring in a material per unit time (see Curie, Becquerel). The term for activity per unit mass is specific activity. 

Curie (Ci)—A unit of radioactivity. One curie equals that quantity of radioactive material in which there are 3.7xl010 nuclear transformations per second. The activity of 1 gram of radium is approximately 1 Ci. 

Disintegration, Nuclear—A spontaneous nuclear transformation (radioactivity) characterized by the emission of energy and/or mass from the nucleus. When large numbers of nuclei are involved, the process is characterized by a definite half-life (see Transformation, Nuclear). 

Fission, Nuclear—A nuclear transformation characterized by the splitting of a nucleus into at least two other nuclei and several neutrons, and is accompanied by the release of a relatively large amount of energy. 

Radioactivity—Spontaneous nuclear transformations that result in the formation of new elements. These transformations are accomplished by emission of alpha or beta particles from the nucleus or by the capture of an orbital electron. Each of these reactions may or may not be accompanied by a gamma photon. 

Gamma (y) (e.m. photon) — 0 10keV-3 MeV b b Photon from nuclear transformation... 

Andersen T (1979) in Harbottle G, Maddock AG (eds) Chemical Effects of Nuclear Transformations in Inorganic Systems, North-Holland, Amsterdam, p 403... 

The classic example of reactions of this type is a sequence of radioactive decay processes that result in nuclear transformations. The differential equations that govern kinetic systems of this type are most readily solved by working in terms of concentration derivatives. For the first reaction,... 

Nuclear dating has been most helpful in establishing the history of the earth and of the moon and of the meteorites. The fact is, there is no other way of measuring their ages. Prior to the discovery of natural radioactivity in the late 19th century, indirect methods were used to estimate the age of the earth, but there were no real answers until the radioactivity of thorium, uranium, and potassium were discovered and we began to understand atomic structure and to realize that nuclear transformation was essentially independent of the chemical form. 

Chemical forms with at least one radioactive atomic nucleus are radioactive substances. The capability of atomic nuclei to undergo spontaneous nuclear transformation is called radioactivity. Nuclear transformations are accompanied by emission of nuclear radiation (Severa and Bar 1991). The average number of nuclei that disintegrate per unit time (= activity) is directly proportional to the total number of radioactive nuclei. The time for 50% of the original nuclei to disintegrate (= half-life or Tb 1/2) is equal to In 2/decay constant for that element (Kiefer 1990). Radiations... 

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